steam turbine speed

Hello

To increase turbine speed you need more steam flow. As you know flow=speed x pipe section area. Next your turn....

Steam velocity will follow the turbine speed. A turbine is typically speed regulated by adjusting the steam inlet valve. If a turbine is driving a generator for example, and that generator sees a higher load, the generator will slow the turbine down causing the steam flow to drop. The governer will open the steam valve to drive the turbine faster. This will increase the steam velocity along with the turbine.

Remember, it is the steam that is driving the turbine, not the turbine that is pushing the steam. The faster the turbine is running, the less energy is lost by the steam and the greater the exit velocity.

The steam is at its highest velocity when it enters the turbine, the steam reacts with the first set of blades which are small in relationship with the last row of blades which are much larger, as the steam expands through the turbine its velocity is reduced. The small blades and the large blades are rotating at the same speed, RPM, but the work done by the high velocity steam on the small blades is the same as the work done by the larger blades with reduced velocity (reduced pressure and velocity, larger expanded volume of steam working on larger blade). For this to be correct the steam passing through the turbine blades has always to be higher than the turbine speed, and though the velocity of the steam at the exhaust is reduced it is still greater than the turbine speed, thus allowing it to do work.

Regards JD.